High strength woven fabrics are often utilized as a reinforcement in a wide variety of products, such as belts, hoses, and tires. The process utilized in making such high strength woven fabrics has traditionally involved (a) spinning a polymeric material into a fully drawn yarn: (b) twisting at least two fully drawn polymeric yarns into a cord; and (c) weaving a plurality of said cords into a greige woven fabric. Such greige woven fabrics are commonly treated with various chemical agents before incorporation into products. For example, greige woven tire fabric is normally treated in a resorcinol-formaldehyde-latex (RFL) dip before incorporation into tires.
The yarns utilized in making cords for incorporation into high strength fabrics have traditionally been fully drawn in order to attain the required combination of mechanical properties. For instance, fully drawn yarns are utilized in order to provide high strength. The incorporation of yarns which are not fully drawn into high strength fabrics utilizing conventional techniques results in a substandard product. For this reason, virtually all conventional tire cords are manufactured utilizing fully drawn yarns.
There are many problems associated with making fully drawn yarns. For instance, filaments in fully drawn yarns commonly break in the process of being drawn. In a commercial process this problem of breakage causes downtime and waste and is highly undesirable. Fully drawn yarns can also be damaged due to overdrawing. For example, white streaking and broken filaments (fuzziness) frequently occur in the process of fully drawing yarns. These problems become more acute as spinning speeds are increased, and the trend today is toward higher and higher spinning speeds in order to increase throughputs and to improve dimensional stability. The majority of these problems are virtually eliminated when yarns are less than fully drawn (incompletely drawn). Unfortunately, in the past it has not been possible to utilize incompletely drawn yarns in manufacturing high strength fabrics of high quality.